This invention relates to an apparatus for making tubular film with transverse closure strips for bag making purposes.
Heretofore it has been conventional to produce plastic bag making material from extruded or cast film, provided integrally with or having attached thereto extruded reclosable fastener strip means extending longitudinally parallel to the extrusion axis of the film. A prior art example along this line is found in U.S. Pat. No. Re. 29,208 which discloses the integral tubular extrusion of the film, and longitudinally extending separable fastener means on the inside of the tube.
Attachment of separately formed separable closure means longitudinally to a tubular film is exemplified in U.S. Pat. No. 3,532,571.
Recently it has been proposed, in copending application of Paul B. Christoff and Steven Ausnit, Ser. No. 837,161 filed Mar. 7, 1986, now U.S. Pat. No. 4,655,862 to provide a method of apparatus for providing bag making film onto which separately formed fastener strips are attached in crosswise, i.e. perpendicular position, relative to the formation axis or length of the film. While this structure has advantageous capabilities, such for example as for use in a vertical bag forming, filling and sealing machine, production costs for making the material may be relatively high.